JPH0958394A - Gas generator for air bag device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To break a seal plate securely and emit high pressure gas securely by providing a cutting blade section which breaks a sealing member in a travelling member and changing the shape of a cross section of the sealing member at a position where the cutting blade section of the travelling member comes into contact or in its vicinity. SOLUTION: A cylinder chamber 16 for mounting gas cylinder is formed in a main body 14, and a seal plate 17 is provided in an upper end opening of a gas cylinder 15. Moreover, a cutting blade section 23 of which shape resembles a round blade of a graver is provided at a tip of a piston 22 provided inside the cylinder chamber 16. Moreover, a peripheral part of the seal plate 17 is an annular flat plate section 36, and its central part is a projection section 37. Changes in the shape of a cross section in a boundary part between them is incontinuous, and a cutting blade section 23 of the piston 22 is brought into contact with the boundary part. When a detonating member 32 acts by a collision sensor of a vehicle, the piston 22 is pushed out, and the cutting blade section 23 shears the seal plate 17 in arc shape. At this time, the concentration of stress occurs in a part where the shape of the cross section is changed so that shearing is done instantaneously.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas generator suitable for use in a vehicle airbag device, and more particularly to a gas generator for an airbag device using a mixed gas of a compressed gas source and a gas generated by a gas generating agent. Regarding the device.

[0002]

2. Description of the Related Art As a method of inflating an airbag,
By using the gas pressure of the gas cylinder, the gas can be ejected by piercing the sealing plate of the gas cylinder with a sharp arrow whose tip is sharpened by shock detection and sending it into the airbag, or the explosive power of the explosive by an electric heater. A method of utilizing the gas generating agent to gasify it by a chemical reaction is known. Among them, there is a conventional gas generator for an airbag device, which employs a method of ejecting gas by utilizing the gas pressure of a gas cylinder and sending the gas into an airbag, as shown in FIG. In FIG. 13, reference numeral 1 represents a main body screwed to a fixed plate 2, and a cylinder chamber 4 for mounting a gas cylinder 3 is formed in the main body 1. A sealing plate 5 is attached to the upper end opening of the gas cylinder 3, and the gas cylinder 3 is mounted below the cylinder chamber 4. Further, the fixing plate 2 is provided below the cylinder chamber 4.
An ejection port 6 for ejecting the gas in the gas cylinder 3 is formed toward the front, and a piston 7 is arranged inside the cylinder chamber 4. Furthermore, the main body 1 of the fixed plate 2
An air bag 8 communicating with the ejection port 6 is attached to the opposite side (that is, the back side). Piston 7
Is urged and supported inside the cylinder chamber 4 by a spring 9 in a direction opposite to the moving direction during the opening operation. Further, although not shown in FIG. 13, a detonating member is provided in a portion of the main body 1 which communicates with the cylinder chamber 4.

In such a structure, when an impact sensor (not shown) detects a vehicle collision or the like and activates the detonating member to apply an explosive pressure to the cylinder chamber 4, the head of the piston 7 receives this and the piston 7 receives it. Is instantly pressed downward in the cylinder chamber 4, and the sealing plate 5 of the gas cylinder 3 is pierced by its tip. As a result, the gas in the gas cylinder 3 is ejected, and the pressure and the elastic force of the spring 9 cause the piston 7 to return almost upward to the cylinder chamber 4 in a nearly reactionary manner. The gas ejected from the gas cylinder 3 is ejected from the cylinder chamber 9 through the ejection port 6 to the back side of the fixed plate 2,
The folded airbag 8 is instantly inflated.

[0004]

However, in such a conventional gas generating device for an airbag device,
Although the piston 7 returns to its original position immediately after breaking the sealing plate 5 during the gas ejection operation and does not prevent the ejection of gas from the gas cylinder 3, it has a basic configuration for optimizing the gas ejection characteristics. There is a growing demand for greater freedom. Further, while the gas is being ejected from the gas cylinder 3 to the airbag 8, there is a tendency that the gas cylinder 3 undergoes adiabatic expansion of the gas to lower the temperature and the ejection force of the gas is decreased.

The present invention has been made in view of the above problems, and a first object of the present invention is to provide a gas generator for an air bag device capable of reliably breaking a sealing plate. is there.

Another object of the present invention is to provide a gas generator for an air bag system which can swiftly and reliably perform a piston movement of a moving member.

Still another object of the present invention is to provide a gas generator for an air bag device which can suppress the temperature drop of the gas cylinder during gas ejection to the maximum.

In view of the above, it is an object of the present invention to provide a gas generator for an air bag device which can surely optimize the gas ejection characteristics into the air bag.

[0009]

In order to achieve the above object, the present invention provides a compressed gas storage container in which compressed gas is stored while being sealed by a sealing member, and energy that is activated in response to an input signal. An energy applying unit that can be applied; and a moving member that moves by receiving the energy applied by the energy applying unit and breaks the sealing member of the compressed gas storage container. At least a part of the gas generating device for an airbag device that releases gas from the compressed gas storage container into the airbag by rupture, at the tip of the moving member, abutting the sealing member and breaking the sealing member Is provided with an arcuate cutting edge portion, and the sealing member is used, and the cross-sectional shape is changed at or near the position where the cutting edge portion of the moving member abuts when the sealing member is broken. The gist. It is preferable that the cross-sectional shape change of the sealing member in the vicinity of the position where the cutting edge portion of the moving member comes into contact is discontinuous.

In another aspect of the present invention, in addition to the above aspects, a gas generating agent that receives the energy applied by the energy applying means to generate a gas, a gas released from a compressed gas storage container, and the gas The gist is that a mixing chamber for mixing the gas generated from the generating agent is provided, and the gas mixed in the mixing chamber is discharged into the airbag.

In another aspect of the present invention, the structure of the moving member and its moving stroke are adjusted so that the gas from the compressed gas storage container is released into the mixing chamber earlier than the gas from the gas generating agent. That is the summary.

According to another aspect of the present invention, the cutting blade portion of the moving member has an arc shape extending over an angle of 120 to 300 degrees, or a substantially semicircular shape, and the cutting blade portion is on the compressed gas storage container side. It is preferable that the angle becomes acute toward. Further, as an example of the changed sectional shape of the sealing member, there is one in which the corresponding portion of the sealing member is formed in a convex shape toward the moving member side. Further, since the cutting blade portion of the moving member has an arc shape, the sealing member has at least a part of a portion corresponding to the inside of the arc shape of the cutting blade portion when the gas is released from the compressed gas storage container. The moving member is connected to a portion corresponding to the outside of the arcuate shape of the cutting edge portion.

Further, according to another aspect of the present invention, the moving member is held between the moving member and the sealing member when the moving member is stationary, and the movement is substantially caused when the moving member moves. An unobstructed holding member is provided. A metal mesh member may be provided between the gas generating agent and the mixing chamber.

Further, in another aspect of the present invention, a plurality of compressed gas storage containers are provided, and the arcuate size of each cutting blade portion of the moving member corresponding to each sealing member of the plurality of compressed gas storage containers. May be set to be different from each other. Further, in the gas generator for an air bag device of the multi-compressed gas storage container type, the moving member is a single moving member, and the single moving member is provided with a plurality of cutting blade portions, and further, A positioning member that defines the relative position of the single moving member and the plurality of compressed gas storage containers may be provided.

Regardless of the single compressed gas storage container type or the multiple compressed gas storage container type, a diffuser means can be provided near the compressed gas storage container with a filter member built in and the opening facing the compressed gas storage container. Further, the sealing member can be molded so that when the pressure inside the compressed gas container rises abnormally when the gas generator is not operating, a part of the sealing member breaks before the other part.

[0016]

According to the present invention, the tip of the moving member has the following structure.
At least a part of the cutting member that abuts on the sealing member and breaks the sealing member is provided with an arcuate cutting edge portion, and the sealing member serves as a cutting blade of the moving member when the sealing member is broken. When the cutting edge part abuts the sealing member and breaks this sealing member (breaking due to shearing) because the cross-sectional shape is changed at or near the position where the parts abut, the high pressure gas pressure in the compressed gas container Due to this, stress concentration occurs in a portion having a low proof stress in which the cross-sectional shape of the sealing member is changed, so that shearing is instantaneously performed in the portion where the cutting edge portion abuts.
The ruptured portion of the contacted portion due to shearing extends along the shape of the sealing member whose cross-section changes, and the rupture progresses when the gas pressure acting on the sealing member and the proof stress of the sealing member are balanced. It stops, while the sealing member is pushed up parallel to the outflow direction of the gas and remains unimpeded in the flow of the released gas. The stress concentration occurs more effectively when the cross-sectional shape change of the sealing member at the position where the cutting edge portion of the moving member contacts or in the vicinity thereof is discontinuous, and shearing of the sealing member also occurs. It is done smoothly. This releases high pressure gas from the compressed gas container.

Further, in another aspect of the present invention, in addition to the above aspects, a gas generating agent which receives the energy applied by the energy applying means to generate a gas, a gas released from a compressed gas storage container, and the gas. By providing a mixing chamber for mixing the gas generated from the generating agent and releasing the gas mixed in the mixing chamber into the airbag, a larger amount of gas can be discharged in an appropriate state (too high temperature). Without)
Can be sent to airbags. In this case, if the structure of the moving member and its moving stroke are adjusted so that the gas from the compressed gas storage container is released into the mixing chamber earlier than the gas from the gas generating agent, the airbag for the gas is Injects well into the interior.

Further, the cutting edge portion of the moving member is 120 degrees to 3 degrees.
It has an arc shape extending over an angle of 00 degrees or a substantially semicircular shape, and if this cutting edge portion is formed at an acute angle toward the compressed gas storage container side, the corresponding portion of the sealing member can be smoothly broken. . Further, since the cutting blade portion of the moving member has an arc shape, the sealing member has at least a part of a portion corresponding to the inside of the arc shape of the cutting blade portion when the gas is released from the compressed gas storage container. When the gas is released from the compressed gas storage container, it can be connected to a portion corresponding to the outer side of the arc shape of the cutting member of the moving member and can be broken without disconnecting a part of the sealing member from other parts. There is no risk that broken pieces of the sealing member will scatter and block the gas passage. Moreover, as an example of the changed cross-sectional shape of the sealing member, when the corresponding portion of the sealing member is formed in a convex shape toward the moving member side, a fragmented portion rises due to breakage of the sealing member. Well done.

Further, when the holding member is provided between the moving member and the sealing member, malfunctions when the gas generator is not operating can be prevented. Further, when a metal mesh member is provided between the gas generating agent and the mixing chamber, the residue (burnt residue) generated at the time of combustion of the gas generating agent is filtered, and at the same time, combustion of the generated gas can be promoted. .

Further, in another aspect of the present invention, a plurality of compressed gas storage containers are provided, and each cutting blade portion of the moving member corresponding to each sealing member of the plurality of compressed gas storage containers has a substantially semicircular shape. If the sizes are set to be different from each other, the amount of gas released from each compressed gas storage container per unit time can be made different to adjust the inflation rate of the airbag. And, in the gas generating device for the airbag apparatus of the multiple compressed gas storage container type, the moving member is a single moving member,
The structure can be further simplified by providing a plurality of cutting blades on the single moving member, and further, a positioning member for defining the relative position between the single moving member and the plurality of compressed gas storage containers is provided. This makes it possible to move the moving member along the correct path.

Regardless of the single compressed gas storage container or the multiple compressed gas storage container type, by providing a diffuser means in the vicinity of the compressed gas storage container with a filter member and an opening facing the compressed gas container. In addition to being able to more completely carry out the filtering operation of the residue generated at the time of combustion of the gas generating agent, the gas flowing out from the diffuser means (the temperature is high because the gas generated by the combustion of the gas generating agent is contained) By turning the compressed gas storage container toward this side, it is possible to warm the compressed gas storage container and prevent a temperature drop due to adiabatic expansion. Further, when the pressure inside the compressed gas container rises abnormally when the gas generator is not operating, the sealing member is molded so that a part thereof breaks before the other part, so that the gas generator It is possible to prevent the compressed gas storage container from exploding in the event of another accident such as a vehicle fire when is not operating.

Various features of the present invention as described above, and other features will be more apparent from the following description with reference to the drawings.

[0023]

【Example】

(Embodiment 1) FIGS. 1 and 2 are sectional views showing a first embodiment of a gas generator for an airbag device according to the present invention. Of these, FIG. 1 shows a state in which the gas generator is not used (or inoperative), and FIG. 2 shows a state in which the gas generator is activated to inflate the airbag. In FIG. 1, reference numeral 11 is a case accommodating a gas generator,
The fixed plate 1 for attaching the airbag 12 to the tip portion thereof
3 is fixedly attached. Reference numeral 14 denotes a main body of the gas generator housed inside the case 11, and the main body 14
A cylinder chamber 16 for mounting a gas cylinder 15 as a compressed gas storage container is formed therein. The gas cylinder 15 is high-pressure filled with an inert gas such as argon,
A sealing plate 17 as a sealing member is attached to the upper end opening. The gas cylinder 15 is attached to the lower portion of the cylinder chamber 16 by screwing or other method. Further, a combustion chamber 19 is formed around the outside of the cylinder chamber 16 and is separated by a wall portion 18 to accommodate the gas generating agent 20 therein and to burn the gas generating agent 20. In addition, in the lower portion of the cylinder chamber 16 of the main body 14, the first ejection port 21 (FIG.
Inside, the body 14 is formed to extend obliquely downward), and a piston 22 as a moving member is arranged inside the cylinder chamber 16.

The piston 22 is slidably arranged inside the cylinder chamber 16, and its tip portion is forward (downward in FIG. 1) from the end face of the piston 22, that is, the gas cylinder 15.
A cutting edge portion 23 that projects toward the sealing plate 17 is provided. The wall portion 18 of the cylinder chamber 16 is provided with a stopper 18a that projects inward from the wall portion in the radial direction, and receives the piston 22 sliding inside the cylinder chamber 16 to determine its movement stroke. A holding member 33 that holds the piston 22 at a position apart from the sealing plate 17 attached to the gas cylinder 15 is interposed between the stopper 18a and the piston 22 when the gas generator is not operating. There is. The holding member 33 is formed by molding a thin resin or metal into a structure that is easily deformed, or formed into a hollow structure or a porous structure.

The cylinder chamber 16 and the combustion chamber 19 are communicated with each other by an opening 24 formed in the wall portion 18.
The opening 24 is closed by a piston 22 in a normal state, and the piston 22 moves downward in the cylinder chamber 16 so that the cutting edge portion 23 abuts the sealing plate 17 and the sealing plate 17 is broken. Opening 2 so that it can be opened later
The position of No. 4, the length of the piston 22 and the moving stroke of the piston 22 are set. The case 11 has a structure in which both divided bodies of the front end side case piece 11a and the base end side case piece 11b are joined at a joint 25, and a flange portion 26 provided at the center of the inside of the base end side case piece 11b. ,
By appropriately setting the length dimension of the wall portion 18 provided in the central portion of the main body 14, a gap is formed between both members when the distal side case piece 11a and the proximal side case piece 11b are joined. It can be formed into an opening 24. Or
A through hole may be formed as the opening 24 in the flange portion 26 and / or the wall portion 18, or both of them. Further, in the lower portion of the combustion chamber 19 of the main body 14, there is provided a second ejection port 27 (which extends downward in the vertical direction to the main body 14 in FIG. 1) for releasing the gas generated by the gas generating agent 20. Has been formed.

A space is formed between the case 11 and the gas cylinder 15 housed and arranged in the case 11, and the gas released from the gas cylinder 15 and the gas generated by the gas generating agent 20 are mixed. A chamber 28 is formed. The first jet outlet 21 and the second jet outlet 27 both communicate with the mixing chamber 28. Further, the case 11 and the airbag 12 are fixedly coupled to each other with the tip portion of the case 11 inserted in the airbag 12, and a plurality of discharge ports 29 are formed at the tip of the case 11. In the combustion chamber 19, a mesh 30 member is installed in the front part of the inlet of the second ejection port 27. In addition, in the mixing chamber 28, a mesh member 31 is installed in the front part of the discharge port 29. In this embodiment, the mesh members 30 and 31 are made of metal.

Further, the first seal member 3 is provided at the inlet (on the side of the combustion chamber 19) of the second jet port 27 provided in the main body 14.
4 is loaded, while the second seal member 35 is loaded at the outlet (mixing chamber 28 side). These sealing members 34 and 35 are made of, for example, a thin sheet made of aluminum or other metal film tape, and the sheet or film tape is bonded with an adhesive so as to close the inlet and the outlet of the second ejection port 27. It is configured by being attached to the main body 14. As described above, by loading the seal members 34 and 35, the combustion chamber 19 is maintained as a space independent from the mixing chamber 28, so that the gas generating agent 20 is kept constant even if it is not used for a long time. Performance (or characteristics) can be maintained. Further, the first seal member 34 can withstand a considerably large pressure (about 60 atm as an example), and also has a role of accumulating the pressure at the time of ignition of the gas generating agent 20 and improving its ignitability. There is. On the other hand, the second seal member 35 is attached for the purpose of maintaining the confidentiality of the combustion chamber 19, and is torn with a small pressure (for example, 2 to 3 atmospheres). The second seal member 35 is also loaded in the mixing chamber 28 side outlet of the first ejection port 21 and closes this outlet. Further, a detonating member 32 as an energy applying means is provided at the upper end portion of the cylinder chamber 16 of the main body 14 or the central portion of the base end side case piece 11b. The detonating member 32 is electrically connected to a collision sensor attached to the vehicle.

The configuration of the sealing plate 17 will be described here. The sealing plate 17 has a cross-sectional shape that changes at or near the position where the cutting edge portion 23 of the piston 22 contacts when the sealing plate is broken. As shown in FIG. 3, for example, as shown in FIG. 3, an annular flat plate portion 36 is formed on the peripheral portion of the sealing plate 17, while the sectional shape of the sealing plate 17 is changed to the piston shape. This is realized by forming a dome-shaped convex portion 37 having a radius of curvature R toward the 22 side. In the case of FIG. 3, the cross-sectional shape change is discontinuous at the boundary portion from the flat plate portion 36 to the convex portion 37, and the cutting edge portion 23 of the piston 22 comes into contact with this boundary portion. ing. As shown in this figure, the cutting blade portion 2 of the piston 22 of the sealing plate 17
Since the cross-sectional shape change in the vicinity of the position where 3 abuts is discontinuously performed, stress concentration effectively occurs when the cutting edge portion 23 abuts on the sealing plate 17. Also the sealing plate 1
As shown in FIG. 4, by further processing 7,
At the apex portion of the convex portion 37 of the sealing plate 17, a recess 38 having a smaller wall thickness than other portions is provided. FIG. 5 is a perspective view showing an example of the sealing plate 17 provided with the recess 38. By providing this recess 38, when the pressure inside the gas cylinder 15 rises abnormally due to a vehicle fire or the like when the gas generator is not operating, this recess 38 breaks before the other parts, and the compressed gas is compressed. To prevent the gas cylinder 15 from exploding.

Next, the cutting edge portion 2 attached to the piston 22
The configuration of No. 3 will be described. As shown in FIG. 6, the cutting blade portion 23 has the same basic structure as that of a cylindrical body having a circular cross section cut in the longitudinal direction (a structure similar to the round blade of a chisel). As shown in FIG. 7, the cutting edge portion 23 has, for example, an arc shape having a cross section of an angle of 120 to 300 degrees, and an example thereof is a substantially semicircular shape. The cross-sectional shape of the cutting edge portion 23 may be a shape other than a circular arc. In addition, the tip of the cutting blade portion 23 has a sealing plate 1 as shown in FIG.
It is formed in an acute angle toward the 7 side, and has a structure capable of abutting the sealing plate 17 and breaking the sealing plate 17 by a shearing action. The cutting blade portion 23 is detachably provided to the piston 22, and various cutting blade portions (having different arc angles, a cutting blade portion having a cross-sectional shape other than the circular arc, Or a cutting edge part with a cross-sectional shape that includes a straight part in part)
Can be exchanged.

The operation of the gas generator for an airbag device having the above structure will be described. First, when the gas generator is not operating, the piston 22 is held above the cylinder chamber 16, and the cutting edge portion 23 and the gas cylinder 1 are held.
5 has a positional relationship with the sealing plate 17 shown in FIG. In this state, when an electric signal from the collision sensor of the vehicle is applied, the detonation member 32 operates. The energy of the high-pressure gas generated by the explosion of the detonation member 32 pushes the piston 22 toward the gas cylinder 15, crushes or destroys the holding member 33 holding the piston 22 and rushes toward the sealing plate 17. . Since the piston 22 is provided with a detachable arcuate cutting edge portion 23, the cutting edge portion 23 is first moved to the boundary portion between the flat plate portion 36 and the convex portion 37 of the sealing plate 17 by the thrust of the piston 22. Abut. As a result, stress concentration occurs in the boundary portion, and the tip of the cutting edge portion 23 formed into an acute angle bites into the sealing plate 17 and shears the sealing plate 17 into an arc shape. When a part of the sealing plate 17 is sheared in an arc shape, the remaining arcuate sealing portion of the sealing plate 17 is torn by the action of the high-pressure gas inside the gas cylinder 15, and the sealing plate 17 is removed.
As shown in (b), it is almost completely unsealed in a state where a part is connected to the gas cylinder 15 side. As a result, the high-pressure gas passes through the first ejection port 27 and the first ejection port 27
The second seal member 35 that closes the outlet of is broken and begins to flow into the mixing chamber 28.

After the sealing plate 17 of the gas cylinder 15 is opened, the piston 22 further moves by a constant stroke. By this further movement, the piston 22 opens the opening 24 that connects the cylinder chamber 16 and the combustion chamber 19. As a result, the flame from the detonating member 32 reaches the gas generating agent 20 in the combustion chamber 19 through the opening 24 and ignites the gas generating agent 20. The combustion chamber 19 becomes high temperature and high pressure due to the combustion heat of the gas generating agent 20, but the first seal member 34 withstands until the inside of the combustion chamber 19 reaches about 60 atm, so that the combustion of the gas generating agent 20 is sufficiently performed. Then, when the pressure in the combustion chamber 19 reaches a predetermined pressure, the first seal member 34 is destroyed, and the combustion gas flows out from the second ejection port 27 into the mixing chamber 28, and already flows into the mixing chamber 28. Mixed with inert compressed gas. The combustion gas is promoted to complete combustion by passing through the mesh member 30 provided adjacent to the first seal member 34 in the combustion chamber 19. Further, the mesh member 30 serves as a filter for lowering the temperature of the combustion gas released by the heat of the combustion gas being deprived of by the mesh member 30 and for capturing the combustion residue.

The combustion gas discharged from the second outlet 27 is filled in the mixing chamber 28 formed by the gas cylinder 15 and the case 11 covering the circumference of the gas cylinder 15, and the temperature is lowered by the discharge of the compressed gas by adiabatic expansion. While warming the gas cylinder 15 and assisting the discharge speed, the airbag 12 is inflated through the discharge port 29 provided at the tip of the case 11.
Since a mesh member 31 is provided in a part of the mixing chamber 28 in order to capture the combustion residue that causes smoke, the combustion gas is doubly filtered. In this example,
Although the mesh member 31 is attached near the inlet of the discharge port 29, it may be attached at another place, for example, near the outlet of the second ejection port 27.

(Embodiment 2) FIGS. 10 to 12 are sectional views showing a second embodiment of a gas generator for an airbag device according to the present invention. Of these, FIG. 10 is a front sectional view showing a state when the gas generator is inoperative, and FIG. 11 is a side sectional view showing a state when the gas generator is inoperative, and FIG.
FIG. 4 is a front cross-sectional view showing a state in which the gas generator is activated and the airbag is inflated. The gas generating apparatus according to this embodiment has a plurality of gas cylinders 15 (two gas cylinders in this embodiment) and the gas generating apparatus according to the first embodiment except that it has a configuration according to this aspect. Since the device has basically the same structure as the device and operates in the same manner, the same parts as those in the first embodiment are designated by the same reference numerals.

In FIG. 10, reference numeral 51 is a case for accommodating the gas generator, and is composed of a front end side case piece 51a and a base end side case piece 51b. Reference numeral 52 is a fixing plate that is joined to the tip portion of the tip side case piece 51a and that mounts the airbag 12 on the opposite side of the tip side case piece 51a. Reference numeral 53 designates a front end side case piece 51a and a base end side case piece 5
It is a partition plate which is sandwiched between 1b and 1b and supports two gas cylinders 15 at a fixed interval. Reference numeral 54 denotes a lid member that closes the upper end of the base end side case piece 51b. The base-side case piece 51b, the partition plate 53, and the lid member 54 constitute the main body 50 of the gas generator.

In the main body 50, an initiating member 32 electrically connected to a collision sensor attached to the vehicle is installed at an upper end portion of the inside of the main body 50, and a piston 56 as a moving member is provided adjacent to the initiating member 32 and downward. A cylinder chamber 55 that slidably accommodates is formed. The gas cylinder 15 is filled with an inert gas such as argon under high pressure, and a sealing plate 17 as a sealing member is attached to the upper end opening thereof. The gas cylinder 15 is attached to a predetermined position of the partition plate 53 by screwing or the like. Further, a combustion chamber 19 is formed around the outer periphery of the cylinder chamber 55, which is separated by the wall portion 18, accommodates the gas generating agent 20 therein, and burns the gas generating agent 20. Below the combustion chamber 19 in the main body 50, a mixing chamber 60 defined by the base end side case piece 51b and the partition plate 53.
Are formed. The combustion chamber 19 and the mixing chamber 60 are communicated with each other by the third ejection port 58, and the upper end opening of the gas cylinder 15 is directly communicated with the mixing chamber 60.

At the tip of the piston 56, the piston 56
Two cutting edge portions 56 projecting from the end faces of the two gas cylinders 15 toward the respective sealing plates 17 are provided. Since the two cutting edge portions 56 are provided in this manner, the piston 56 is formed in a structure having a substantially inverted T-shaped cross section. A pin 59 is planted at a predetermined position on the partition plate 53, while a hole 65 through which the pin 59 passes is formed at a portion of the piston 56 corresponding to the pin 59. And the through hole 65 allow the piston 56 to move into the cylinder chamber 5
5 constitutes a guide member that slides correctly along 5. Further, between the partition plate 53 and the piston 56, a holding member 61 that holds the piston 56 at a position apart from the sealing plate 17 attached to the gas cylinder 15 when the gas generator is inoperative is interposed. There is. This holding member 6
The pin 59 is composed of a hollow O-ring or the like made of a material that is easily deformable, such as plastic.
It is attached to. Further, the cylinder chamber 55 and the combustion chamber 19
And are communicated with each other through an opening 24 formed in the wall portion 18. The opening 24 is closed by a piston 56 in a normal state, and the piston 56 moves downward in the cylinder chamber 55 so that the cutting edge portion 56 abuts on the sealing plate 17 and the sealing plate 17 is broken. The position of the opening 24, the length dimension of the piston 56, and the moving stroke of the piston 56 are set so that they can be opened later.

A space is formed between the case 51 and the gas cylinder 15 housed in the case 51, and the gas released from the gas cylinder 15 and the gas generated by the gas generating agent 20 are mixed. An induction chamber 62 to be introduced later is formed. Case 5 in this induction chamber 62
A diffuser pipe 63 that guides the mixed gas from the mixing chamber 60 to the induction chamber 62 is provided in the space formed between the one wall portion and the gas cylinder 15. This diffuser tube 63
Is composed of a cylindrical body having a circular cross section that extends in the up-down direction from the upper end to the lower end in the guide chamber 62, and through holes 64 are formed on the side surfaces of the diffuser pipe 63 toward the respective gas cylinders 15. Through-hole 64 is for each gas cylinder 15
On the other hand, a plurality of diffuser tubes 63 are formed at regular intervals in the longitudinal direction so that the gas can be blown almost all over the longitudinal direction. Then, inside the diffuser pipe 63, a filter mesh 69 is installed in front of the through hole 64. Diffuser tube 63
Is provided so as to face the gas cylinder 15 while cooling the hot mixed gas flowing into the diffuser pipe 63 to some extent and capturing the combustion residue which becomes a smoke component through the built-in filter mesh 69. Through hole 6
It is provided for ejecting gas toward the gas cylinder 15 from No. 4.

The case 51 and the airbag 12 are
The case 51 is connected via a fixed plate 52 attached to the tip portion thereof, and the fixed plate 52 has a plurality of discharge ports 68 formed therein. In the combustion chamber 19, the mesh 30 member is installed in the front part of the inlet of the third ejection port 58. Further, in the guide chamber 62, a mesh member 67 is installed in the front part of the discharge port 68. In this embodiment, the mesh members 66 and 67 are made of metal.

Further, as in the first embodiment, the first seal member 34 is loaded in the inlet of the third jet port 58 provided in the main body 50, while the second seal is in the outlet.
The seal member 35 is loaded.

A sealing plate attached to the gas cylinder 15
The structure and modification of the cutting edge 57 provided on the piston 56 are the same as those of the first embodiment.

The operation of the gas generator for an airbag device having such a configuration will be described. Vehicle collision sensor
The detonating member 32 is actuated by an electric signal from. The energy of the high-pressure gas generated by the explosion of the detonation member 32 pushes the piston 56 toward the gas cylinder 15, crushes or destroys the holding member 61 holding the piston 56 and rushes toward the sealing plate 17. . Since the movement of the piston 56 is guided by the guide member constituted by the pin 59 and the through hole 65, the two cutting edge portions 5
The piston 56 with 7 goes straight through the defined path. Since the piston 56 is provided with two detachable arc-shaped cutting edge portions 57, the cutting edge portion 57 is first projected from the flat plate portion 36 of the sealing plate 17 of each gas cylinder 15 by the thrust of the piston 56. It contacts the boundary portion of the portion 37. As a result, stress concentration occurs at the boundary portion, and the tip of the cutting edge portion 57 formed into an acute angle bites into the sealing plate 17, and shears the sealing plate 17 into an arc shape. When a part of the sealing plate 17 is sheared in an arc shape, the sealing plate 1
The remaining arcuate sealing portion of 7 is torn by the action of the pressure of the high-pressure gas inside the gas cylinder 15, and the sealing plate 17 is almost completely opened, leaving only a part of it on the gas cylinder 15 side. As a result, the high-pressure gas begins to flow directly into the mixing chamber 60.

After the sealing plate 17 of the gas cylinder 15 is opened, the piston 56 further moves by a fixed stroke. By this further movement, the piston 56 opens the opening 24 that connects the cylinder chamber 55 and the combustion chamber 19. As a result, the flame from the detonating member 32 reaches the gas generating agent 20 in the combustion chamber 19 through the opening 24 and ignites the gas generating agent 20. The combustion chamber 19 becomes high temperature and high pressure due to the combustion heat of the gas generating agent 20, but the first seal member 34 withstands until the inside of the combustion chamber 19 reaches about 60 atm, so that the combustion of the gas generating agent 20 is sufficiently performed. Then, when the inside of the combustion chamber 19 reaches a predetermined pressure, the first seal member 34 is destroyed, and the combustion gas flows out of the third ejection port 58 into the mixing chamber 60, and already flows into the mixing chamber 60. Mixed with inert compressed gas. The combustion gas is promoted to complete combustion by passing through a mesh member 66 provided adjacent to the first seal member 34 in the combustion chamber 19. The mesh member 66 also serves as a filter for lowering the temperature of the combustion gas released by the heat of the combustion gas being taken by the mesh member 66 and for capturing the combustion residue.

The combustion gas discharged from the third ejection port 58 is filled in the mixing chamber 60 provided between the gas cylinders 15 and flows into the cylindrical diffuser pipe 63 communicating with the mixing chamber 60. The hot mixed gas that has flowed into the diffuser pipe 63 passes through the filter mesh 69 that is built in, and captures the combustion residue that becomes smoke components, while the gas cylinder 1
The gas is ejected toward the gas cylinder 15 through a through hole 64 provided to face the gas cylinder 5. As a result, the mixed gas becomes
The gas cylinder 15 whose temperature has been lowered by the adiabatic expansion of the compressed gas is warmed to help release the gas, and at the same time, the fine solid residue contained in the combustion gas can be removed by adhering it to the outer wall surface of the cooled gas cylinder 15. It will be possible. The appropriate mixed gas ejected from the through hole 64 passes through the inside of the induction chamber 62 and is discharged from the discharge port 68, so that the airbag 1
Inflate 2. In order to capture the combustion residue that causes smoke, the combustion gas is doubly filtered because a mesh member 67 is also provided in a part of the induction chamber 62. In addition, in this embodiment, the mesh member 67 is attached near the entrance of the discharge port 68, but it is located at another place, for example, the mixing chamber 19
It may be attached in the vicinity of the outlet of the third ejection port 58.
Further, the diffuser can be applied to, for example, a gas generator having the same configuration as that of this embodiment, except that only one cylinder is used instead of a plurality of cylinders.

[0044]

As described above, according to the present invention,
At the tip of the moving member of the gas generator for an airbag device, at least a part of the cutting member that abuts the sealing member and breaks the sealing member is provided with an arcuate cutting edge portion, and the sealing member is used. When changing the cross-sectional shape at or near the position where the cutting edge portion of the moving member abuts at the time of breaking the sealing member, when the cutting edge portion abuts the sealing member and breaks the sealing member, Since stress concentration occurs in the portion where the cross-sectional shape of the sealing member is changed by the action of the high-pressure gas of the gas cylinder, the portion where the cutting edge portion abuts except the portion other than the cutting edge abutment portion. The shearing is instantaneously performed at. This ensures that the high pressure gas is released from the compressed gas container,
A desired gas ejection characteristic can be obtained.

In addition to the above aspects, a gas generating agent that receives the energy applied by the energy applying means to generate a gas, a gas released from the compressed gas storage container and a gas generated from the gas generating agent are included. A mixing chamber for mixing is provided, and the gas mixed in the mixing chamber is discharged into the airbag, so that a larger amount of gas can be sent to the airbag in an appropriate state (without being too hot). Various effects such as being possible can be obtained.

[Brief description of drawings]

FIG. 1 is a front cross-sectional view showing a non-operating state of a gas generator for an airbag device according to a first embodiment of the present invention.

FIG. 2 is a front cross-sectional view showing a state during operation of the gas generator for an airbag device according to the first embodiment.

FIG. 3 is an enlarged sectional view of an essential part for explaining a configuration example of a sealing plate attached to the opening of the gas cylinder in the first embodiment.

FIG. 4 is an enlarged sectional view of an essential part for explaining another configuration example of the sealing plate attached to the opening of the gas cylinder in the first embodiment.

5 is an enlarged perspective view showing the sealing plate shown in FIG. 4;

FIG. 6 is a perspective view showing a configuration example of a cutting blade portion attached to the piston in the first embodiment.

FIG. 7 is an end view of the cutting edge portion shown in FIG. 6 as seen in the direction of arrow A in FIG.

8 is a side view of the cutting edge portion shown in FIG. 6 as seen in the direction of arrow B in FIG.

FIG. 9A is a perspective view showing the positional relationship between the cutting blade portion and the sealing plate when the gas generating device is inoperative. FIG. 9B is a state in which the cutting blade portion breaks the sealing plate when the gas generating device is operating. Perspective view

FIG. 10 is a front cross-sectional view showing a non-operation state of a gas generator for an airbag device according to a second embodiment of the present invention.

FIG. 11 is a side sectional view showing a non-operation state of the gas generator for an airbag device according to the second embodiment of the present invention.

FIG. 12 is a front cross-sectional view showing the operating state of the gas generator for an airbag device according to the second embodiment of the present invention.

FIG. 13 is a front cross-sectional view showing a state in which a conventional gas generating device for an airbag device is inoperative.

[Explanation of symbols]

 11, 51 Case 12 Airbag 13, 52 Fixing plate 14, 50 Main body 15 Gas cylinder (compressed gas storage container) 16, 55 Cylinder chamber 17 Sealing plate (sealing member) 18 Wall 19 Combustion chamber 20 Gas generating agent 21, 27 , 58 Jet port 22, 56 Piston (moving member) 23, 57 Cutting blade part 24 Opening 28, 60 Mixing chamber 29, 68 Discharge port 30, 31, 66, 67 Mesh member 32 Initiating member (energy applying means) 33, 61 Holding member 34, 35 Sealing member 36 Flat plate portion 37 Convex portion 38 Dimple portion 63 Diffuser pipe 64 Through hole 69 Filter mesh

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yasushi Usui 1-1-1, Shimomachiya, Chigasaki-shi, Kanagawa Miyata Industry Co., Ltd.

Claims (14)

[Claims] 1. A compressed gas storage container in which compressed gas is stored while being sealed by a sealing member provided at least in a part, and energy applying means which is activated in response to an input signal and can apply energy. A moving member capable of receiving energy applied by an energy applying means and moving at least a part of a sealing member of the compressed gas storage container, and the compression by the breaking of the sealing member by the moving member. A gas generator for an airbag device, which discharges gas from a gas storage container into an airbag, wherein the moving member is in contact with the sealing member and breaks the sealing member, at least a part of which has an arc shape. Gas for an airbag device having a cutting edge portion, wherein the sealing member has a cross-sectional shape that changes at or near a position where the cutting edge portion of the moving member abuts when the sealing member breaks. Generator. 2. A mixing chamber for mixing a gas generating agent which receives the energy applied by the energy applying means to generate a gas, a gas discharged from the compressed gas storage container and a gas generated from the gas generating agent. 2. The gas generator for an airbag device according to claim 1, further comprising: and discharging the gas mixed in the mixing chamber into the airbag. 3. The gas generator for an airbag device according to claim 2, wherein the gas from the compressed gas storage container is released into the mixing chamber earlier than the gas from the gas generating agent. 4. The cutting edge portion of the moving member is 120 degrees to 300 degrees.
4. The gas generator for an airbag device according to claim 1, which has an arc shape extending over an angle of degrees, and the cutting edge portion forms an acute angle toward the compressed gas storage container side. 5. The arcuate shape of the cutting edge portion of the moving member is a substantially semicircular shape, and the cutting edge portion of the substantially semicircular shape forms an acute angle toward the compressed gas storage container side. 4. The gas generator for an airbag device according to any one of 3 to 3. 6. The gas generator for an airbag device according to claim 1, wherein the sealing member has a cross-sectional shape that is convex toward the moving member. 7. The sealing member is such that at the time of releasing gas from the compressed gas storage container, at least a part of the portion corresponding to the inside of the arc shape of the cutting blade portion of the moving member is an arc of the cutting blade portion of the moving member. 2. The connection with a portion corresponding to the outside of the shape.
7. The gas generator for an airbag device according to any one of 1 to 6. 8. A holding member, which is provided between the moving member and the sealing member, holds the moving member when the moving member is stationary and does not substantially hinder the moving member when the moving member moves. The gas generator for an airbag device according to claim 1, which has. 9. The gas generator for an airbag device according to claim 2, further comprising a metal mesh member between the gas generating agent and the mixing chamber. 10. A plurality of compressed gas storage containers are provided, and the arcuate shapes of the cutting edge portions of the moving members corresponding to the respective sealing members of the plurality of compressed gas storage containers are different from each other. 5. The gas generator for an airbag device according to any one of 1. 11. The moving member is a single moving member, the single moving member is provided with a plurality of cutting blades, and further, the single moving member and a plurality of compressed gas storage containers are provided. 11. A positioning member that defines the relative position of
The gas generator for an airbag device as described in the above. 12. The gas generator for an air bag device according to claim 2, further comprising a diffuser means having a filter member built therein and an opening of which faces the compressed gas container. 13. The sealing member is provided when the pressure inside the compressed gas container rises abnormally when the gas generator is inoperative.
The gas generator for an airbag device according to any one of claims 1 to 12, wherein a part of the gas generator is formed so as to be broken before the other part. 14. The cross-sectional shape change of the sealing member at or near the position where the cutting edge portion of the moving member abuts is discontinuously performed. A gas generator for an airbag device as described.